This invention relates in general to portable air blower apparatus and the like. More specifically, this invention relates to a portable combination blower-vacuum apparatus which is quickly and easily interchangeable between blower and vacuum mode operation.
A variety of vacuum devices are available throughout the prior art, and typically comprise a motor-driven impeller for drawing air at a relatively high rate through a flow path. A suction tube or nozzle forms the inlet to the flow path whereby dirt, leaves, and the like are drawn by the impeller into the flow path for capture within a dust bag formed from a suitable filtering material such as a porous fabric or the like. Importantly, in the prior art, this filtering bag is commonly positioned upstream of the impeller so as to prevent contact between the rotating impeller and the solid material being vacuumed.
The prior art includes some vacuum systems adapted for conversion between blower and vacuum mode operation. More specifically, the prior art discloses the use of an impeller alternatively for drawing air through a dust bag for vacuuming solid material, or for blowing air at a relatively high flow rate at an appropriate surface when the dust bag is removed. However, these prior art combination devices have not been widely used because of their relatively complex construction, and because of the attendant difficulties in switching between blower and vacuum modes of operation.
Portable blower units have recently become popular for use in blowing dirt, dust, leaves, and the like from surfaces such as sidewalks, driveways, etc. These devices have become particularly popular in relatively arid areas wherein water for washing or cleaning of these surfaces is not readily available. These portable blower units comprise a lightweight and inexpensive impeller formed from plastic or the like which is rotatably driven in a correspondingly lightweight and inexpensively-formed centrifugal housing. The impeller draws air axially inwardly through a relatively short inlet flow path, and discharges the air from the housing at a relatively high flow rate for blowing of leaves and the like. However, these portable blowing devices are not readily or conveniently adapted for use in a second mode as a vacuum device. More specifically, the compact, lightweight, and inexpensive housing is not configured for mounting of a dust bag upstream of the impeller, and the lightweight impeller is not adapted to accommodate contact with solid material without clogging or breaking.
The present invention overcomes the problems and disadvantages of the prior art by providing a portable blower-vacuum unit specifically designed for use in a blower mode, or in a vacuum mode. The unit is quickly and easily adjusted between modes, and includes means for protecting a relatively lightweight and inexpensive impeller from damage upon contact with solid material in the vacuum mode.